A Compilation of Current Readings: Leachate Recirculation

Publish Date: 1997

The principal objective of this study was to simulate leachate quantity and quality, as well
as biogas generation at sanitary landfills under both management scenarios of single-pass leaching
and leachate recirculation practices. This objective was satisfied by developing a numerical
model, PITTLEACH-2(1), based on fundamental relationships among hydrologic, hydraulic,
physical/chemical and biological processes of landfill leaching and stabilization. The principles of
unsaturated flow and contaminant transport in porous media were utilized to predict leachate
behavior and landfill stabilization in three general areas, including moisture distribution and flow,
leachate organic strength, and overall methane production. The microbially-mediated processes
of solid waste anaerobic decomposition were simulated in terms of hydrolytic conversion of solid
organic constituents (hydrolysis), acid formation (acidogenesis), and methane fermentation
(methanogenesis). The model predicts the hydrolysis product concentrations, total volatile acid
concentrations, acidogenic and methanorganic populations, methane production rates, and
leachate pH values.